Fluid pumps, and more particularly fuel pumps for pumping fuel, for example, from a fuel tank of a motor vehicle to an internal combustion engine of the motor vehicle, are known. A typical fuel pump includes a housing within which generally includes a pump section, a motor section, and an outlet section. The pump section includes a rotating pumping element, either positive displacement or centrifugal, located axially between an inlet plate and an outlet plate. The pumping element imparts energy into the fuel while forcing the fuel to move from a low pressure state to a high pressure state. An axial clearance is provided between the pumping element and the inlet plate and between the pumping element and the outlet plate such that each axial clearance is large enough to allow the pumping element to rotate freely while being small enough to prevent high pressure fuel from leaking into areas of low pressure. If the axial clearances are excessive, leakage may occur, which results in low flow output of the fuel pump. For perspective, each axial clearance may typically be about 10 to 15 μm for a total of about 20 to 30 μm. The fuel pump typically includes a pre-filter or strainer which is attached to an inlet of the fuel pump in order to strain out large debris from the fuel before the fuel enters the fuel pump. The pre-filter is sized to balance its ability to strain harmful contaminants without creating a flow restriction that can cause cavitation at the inlet of the fuel pump. Consequently, the pre-filter is normally constrained by cavitation considerations in gasoline arrangements or by fuel waxing considerations in diesel fuel arrangements and therefore is not fine enough to strain out all harmful contaminants. As a result, a percentage of the contaminants that enter the fuel pump infiltrate the axial clearances between the pumping element and the inlet plate and between the pumping element and the outlet plate. Infiltration of contaminants into the axial clearances is promoted by pressure gradients which exist between the inlet and radially inner and radially outer portions of the pumping element and by pressure gradients which exist between the outlet and radially inner and radially outer portions of the pumping element since the pressurized fuel that is forced into the axial clearances contains contaminants that passed through the pre-filter. Rotation of the pumping element, together with the presence of contaminants in the axial clearances, results in abrasion which results in wear of the surfaces of the pumping element, inlet plate, and outlet plate, thereby decreasing the flow output of the fuel pump over time due to ever-increasing axial clearances. One example of such a fuel pump is a gerotor-type fuel pump as shown in U.S. Pat. No. 6,769,889 to Raney et al., the disclosure of which is incorporated herein by reference in its entirety. Another example of such a fuel pump is an impeller type fuel pump as shown in United States Patent Application Publication No. 2014/0314591 A1 to Herrara et al., the disclosure of which is incorporated herein by reference in its entirety.
What is needed is a fuel pump which minimizes or eliminates one or more of the shortcomings as set forth above.